Plasma Effect Of Absorption Of Electromagnetic Waves

The Plasma Stealth has been a hot research field in recent years, because the plasma slab has the property of absorbing, reflecting microwaves. When the magnetic field and electron collision frequency have been taken into account, the dielectric tensor should be used to describe the plasma in the problem, and the plasma will be looked as losing material. In this paper, the theorical analysis and computer stimulate calculation have been used to research the reflection of electromagnetic wave of metal plane, metal cylinder and metal sphere, surface of which all have been covered by a plasma slab, and we draw some useful conclusion. High electron collision frequency can cause high absorbing factor, and for microwave of certain frequency, there is a maximum for absorption. High density of plasma also can enforce the absorption of plasma with collision. And if the plasma have high density and electron collision frequency, the influence of magnetic can be neglected. The main work and new method:First, We have given the approximate model of plasma. Using the Primary Theory, the plasma can be dealt with as dielectric and using equation, we can computer its dielectric constant. Then, we have analyzed the plasma slab's property of absorbing electromagnetic waves particularly, and find the influence of all kinds factors, such as electron collision frequency, magnetic field, plasma density, to the property of plasma; We also research the propagation property of TE and TM in plasma, and study the electromagnetic waves' reflection of metal plane with plasma slab, get the power reflecting factor of metal plane in different plasma. Second, we discuss the reflecting property of metal object with plasma slab in cylinder coordinate system and sphere coordinate system. In those cases, the plane waves have been transformed into cylindrical waves or spherical waves separately, and compute the reflecting factor of each spherical wave or cylindrical wave. When the plasma is unhomogeneous, the plasma slab can be divided into many sub-slabs and the solution can be found by using boundary conditions. we analysis several kinds method been using to calculate the RCS of object, and apply Geometrical Optics method to calculate the RCS of object with plasma slab. Using GO, we find a kind simple method to solve problem, which also have enough accuracy. Due to the limitation of GO, the problem can't be solved in many cases, but it does not affect the last conclusion.